{
 "cells": [
  {
   "cell_type": "markdown",
   "id": "301891f2",
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   "source": [
    "# _Categorical_ Data Type\n",
    "\n",
    "\n",
    "`Categoricals` can only take on a limited number of possible values (categories) and <br>\n",
    "can be sorted according to the custom order of the categories.\n",
    "\n",
    "To harness `Categorical` data type in Lets-Plot you can annotate any variable in your dataset as `Categorical` <br> using Lets-Plot `asDiscrete()` function and the `levels` parameter."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "id": "b808bb87",
   "metadata": {},
   "outputs": [
    {
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       "            if(!window.kotlinQueues[\"DataFrame\"]) {\n",
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      "text/html": [
       "                <style>\n",
       "                :root {\n",
       "    --background: #fff;\n",
       "    --background-odd: #f5f5f5;\n",
       "    --background-hover: #d9edfd;\n",
       "    --header-text-color: #474747;\n",
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       "    --text-color-dark: #000;\n",
       "    --text-color-medium: #737373;\n",
       "    --text-color-pale: #b3b3b3;\n",
       "    --inner-border-color: #aaa;\n",
       "    --bold-border-color: #000;\n",
       "    --link-color: #296eaa;\n",
       "    --link-color-pale: #296eaa;\n",
       "    --link-hover: #1a466c;\n",
       "}\n",
       "\n",
       ":root[theme=\"dark\"], :root [data-jp-theme-light=\"false\"], .dataframe_dark{\n",
       "    --background: #303030;\n",
       "    --background-odd: #3c3c3c;\n",
       "    --background-hover: #464646;\n",
       "    --header-text-color: #dddddd;\n",
       "    --text-color: #b3b3b3;\n",
       "    --text-color-dark: #dddddd;\n",
       "    --text-color-medium: #b2b2b2;\n",
       "    --text-color-pale: #737373;\n",
       "    --inner-border-color: #707070;\n",
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       "    --link-color: #008dc0;\n",
       "    --link-color-pale: #97e1fb;\n",
       "    --link-hover: #00688e;\n",
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       "\n",
       "p.dataframe_description {\n",
       "    color: var(--text-color-dark);\n",
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       "\n",
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       "    font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif;\n",
       "    font-size: 12px;\n",
       "    background-color: var(--background);\n",
       "    color: var(--text-color-dark);\n",
       "    border: none;\n",
       "    border-collapse: collapse;\n",
       "}\n",
       "\n",
       "table.dataframe th, td {\n",
       "    padding: 6px;\n",
       "    border: 1px solid transparent;\n",
       "    text-align: left;\n",
       "}\n",
       "\n",
       "table.dataframe th {\n",
       "    background-color: var(--background);\n",
       "    color: var(--header-text-color);\n",
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       "table.dataframe th.bottomBorder {\n",
       "    border-bottom-color: var(--bold-border-color);\n",
       "}\n",
       "\n",
       "table.dataframe tbody > tr:nth-child(odd) {\n",
       "    background: var(--background-odd);\n",
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       "\n",
       "table.dataframe tbody > tr:nth-child(even) {\n",
       "    background: var(--background);\n",
       "}\n",
       "\n",
       "table.dataframe tbody > tr:hover {\n",
       "    background: var(--background-hover);\n",
       "}\n",
       "\n",
       "table.dataframe a {\n",
       "    cursor: pointer;\n",
       "    color: var(--link-color);\n",
       "    text-decoration: none;\n",
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       "\n",
       "table.dataframe tr:hover > td a {\n",
       "    color: var(--link-color-pale);\n",
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       "\n",
       "table.dataframe a:hover {\n",
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       "    text-decoration: underline;\n",
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       "\n",
       "table.dataframe img {\n",
       "    max-width: fit-content;\n",
       "}\n",
       "\n",
       "table.dataframe th.complex {\n",
       "    background-color: var(--background);\n",
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       "    border-left-color: var(--inner-border-color);\n",
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       "\n",
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       "    border-right-color: var(--inner-border-color);\n",
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       "\n",
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       "    width: 8px;\n",
       "    height: 8px;\n",
       "    margin-right: 3px;\n",
       "}\n",
       "\n",
       "table.dataframe .expander {\n",
       "    display: flex;\n",
       "    align-items: center;\n",
       "}\n",
       "\n",
       "/* formatting */\n",
       "\n",
       "table.dataframe .null {\n",
       "    color: var(--text-color-pale);\n",
       "}\n",
       "\n",
       "table.dataframe .structural {\n",
       "    color: var(--text-color-medium);\n",
       "    font-weight: bold;\n",
       "}\n",
       "\n",
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       "    font-weight: bold;\n",
       "}\n",
       "\n",
       "table.dataframe .numbers {\n",
       "    color: var(--text-color-dark);\n",
       "}\n",
       "\n",
       "table.dataframe td:hover .formatted .structural, .null {\n",
       "    color: var(--text-color-dark);\n",
       "}\n",
       "\n",
       "table.dataframe tr:hover .formatted .structural, .null {\n",
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       "\n",
       "\n",
       "                </style>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "%useLatestDescriptors\n",
    "%use lets-plot\n",
    "%use dataframe"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "ce1f82a2",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "Lets-Plot Kotlin API v.4.6.0. Frontend: Notebook with dynamically loaded JS. Lets-Plot JS v.4.2.0."
      ]
     },
     "execution_count": 2,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "LetsPlot.getInfo()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "7decce2b",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "application/kotlindataframe+json": "{\"nrow\":3,\"ncol\":12,\"columns\":[\"untitled\",\"manufacturer\",\"model\",\"displ\",\"year\",\"cyl\",\"trans\",\"drv\",\"cty\",\"hwy\",\"fl\",\"class\"],\"kotlin_dataframe\":[{\"untitled\":1,\"manufacturer\":\"audi\",\"model\":\"a4\",\"displ\":1.8,\"year\":1999,\"cyl\":4,\"trans\":\"auto(l5)\",\"drv\":\"f\",\"cty\":18,\"hwy\":29,\"fl\":\"p\",\"class\":\"compact\"},{\"untitled\":2,\"manufacturer\":\"audi\",\"model\":\"a4\",\"displ\":1.8,\"year\":1999,\"cyl\":4,\"trans\":\"manual(m5)\",\"drv\":\"f\",\"cty\":21,\"hwy\":29,\"fl\":\"p\",\"class\":\"compact\"},{\"untitled\":3,\"manufacturer\":\"audi\",\"model\":\"a4\",\"displ\":2.0,\"year\":2008,\"cyl\":4,\"trans\":\"manual(m6)\",\"drv\":\"f\",\"cty\":20,\"hwy\":31,\"fl\":\"p\",\"class\":\"compact\"}]}",
      "text/html": [
       "        <html>\n",
       "        <head>\n",
       "            <style type=\"text/css\">\n",
       "                :root {\n",
       "    --background: #fff;\n",
       "    --background-odd: #f5f5f5;\n",
       "    --background-hover: #d9edfd;\n",
       "    --header-text-color: #474747;\n",
       "    --text-color: #848484;\n",
       "    --text-color-dark: #000;\n",
       "    --text-color-medium: #737373;\n",
       "    --text-color-pale: #b3b3b3;\n",
       "    --inner-border-color: #aaa;\n",
       "    --bold-border-color: #000;\n",
       "    --link-color: #296eaa;\n",
       "    --link-color-pale: #296eaa;\n",
       "    --link-hover: #1a466c;\n",
       "}\n",
       "\n",
       ":root[theme=\"dark\"], :root [data-jp-theme-light=\"false\"], .dataframe_dark{\n",
       "    --background: #303030;\n",
       "    --background-odd: #3c3c3c;\n",
       "    --background-hover: #464646;\n",
       "    --header-text-color: #dddddd;\n",
       "    --text-color: #b3b3b3;\n",
       "    --text-color-dark: #dddddd;\n",
       "    --text-color-medium: #b2b2b2;\n",
       "    --text-color-pale: #737373;\n",
       "    --inner-border-color: #707070;\n",
       "    --bold-border-color: #777777;\n",
       "    --link-color: #008dc0;\n",
       "    --link-color-pale: #97e1fb;\n",
       "    --link-hover: #00688e;\n",
       "}\n",
       "\n",
       "p.dataframe_description {\n",
       "    color: var(--text-color-dark);\n",
       "}\n",
       "\n",
       "table.dataframe {\n",
       "    font-family: \"Helvetica Neue\", Helvetica, Arial, sans-serif;\n",
       "    font-size: 12px;\n",
       "    background-color: var(--background);\n",
       "    color: var(--text-color-dark);\n",
       "    border: none;\n",
       "    border-collapse: collapse;\n",
       "}\n",
       "\n",
       "table.dataframe th, td {\n",
       "    padding: 6px;\n",
       "    border: 1px solid transparent;\n",
       "    text-align: left;\n",
       "}\n",
       "\n",
       "table.dataframe th {\n",
       "    background-color: var(--background);\n",
       "    color: var(--header-text-color);\n",
       "}\n",
       "\n",
       "table.dataframe td {\n",
       "    vertical-align: top;\n",
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       "\n",
       "table.dataframe th.bottomBorder {\n",
       "    border-bottom-color: var(--bold-border-color);\n",
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       "\n",
       "table.dataframe tbody > tr:nth-child(odd) {\n",
       "    background: var(--background-odd);\n",
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       "\n",
       "table.dataframe tbody > tr:nth-child(even) {\n",
       "    background: var(--background);\n",
       "}\n",
       "\n",
       "table.dataframe tbody > tr:hover {\n",
       "    background: var(--background-hover);\n",
       "}\n",
       "\n",
       "table.dataframe a {\n",
       "    cursor: pointer;\n",
       "    color: var(--link-color);\n",
       "    text-decoration: none;\n",
       "}\n",
       "\n",
       "table.dataframe tr:hover > td a {\n",
       "    color: var(--link-color-pale);\n",
       "}\n",
       "\n",
       "table.dataframe a:hover {\n",
       "    color: var(--link-hover);\n",
       "    text-decoration: underline;\n",
       "}\n",
       "\n",
       "table.dataframe img {\n",
       "    max-width: fit-content;\n",
       "}\n",
       "\n",
       "table.dataframe th.complex {\n",
       "    background-color: var(--background);\n",
       "    border: 1px solid var(--background);\n",
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       "\n",
       "table.dataframe .leftBorder {\n",
       "    border-left-color: var(--inner-border-color);\n",
       "}\n",
       "\n",
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       "    border-right-color: var(--inner-border-color);\n",
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       "\n",
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       "    text-align: right;\n",
       "}\n",
       "\n",
       "table.dataframe .expanderSvg {\n",
       "    width: 8px;\n",
       "    height: 8px;\n",
       "    margin-right: 3px;\n",
       "}\n",
       "\n",
       "table.dataframe .expander {\n",
       "    display: flex;\n",
       "    align-items: center;\n",
       "}\n",
       "\n",
       "/* formatting */\n",
       "\n",
       "table.dataframe .null {\n",
       "    color: var(--text-color-pale);\n",
       "}\n",
       "\n",
       "table.dataframe .structural {\n",
       "    color: var(--text-color-medium);\n",
       "    font-weight: bold;\n",
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       "\n",
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       "}\n",
       "\n",
       "table.dataframe .numbers {\n",
       "    color: var(--text-color-dark);\n",
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       "\n",
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       "    color: var(--text-color-dark);\n",
       "}\n",
       "\n",
       "table.dataframe tr:hover .formatted .structural, .null {\n",
       "    color: var(--text-color-dark);\n",
       "}\n",
       "\n",
       "\n",
       "\n",
       "\n",
       "\n",
       "            </style>\n",
       "        </head>\n",
       "        <body>\n",
       "            \n",
       "<table class=\"dataframe\" id=\"df_654311424\"></table>\n",
       "\n",
       "<p class=\"dataframe_description\">DataFrame: rowsCount = 3, columnsCount = 12</p>\n",
       "<table class=\"dataframe\" id=\"static_df_654311425\"><thead><tr><th>untitled</th><th>manufacturer</th><th>model</th><th>displ</th><th>year</th><th>cyl</th><th>trans</th><th>drv</th><th>cty</th><th>hwy</th><th>fl</th><th>class</th></tr></thead><tbody><tr><td>1</td><td>audi</td><td>a4</td><td>1.800000</td><td>1999</td><td>4</td><td>auto(l5)</td><td>f</td><td>18</td><td>29</td><td>p</td><td>compact</td></tr><tr><td>2</td><td>audi</td><td>a4</td><td>1.800000</td><td>1999</td><td>4</td><td>manual(m5)</td><td>f</td><td>21</td><td>29</td><td>p</td><td>compact</td></tr><tr><td>3</td><td>audi</td><td>a4</td><td>2.000000</td><td>2008</td><td>4</td><td>manual(m6)</td><td>f</td><td>20</td><td>31</td><td>p</td><td>compact</td></tr></tbody></table>\n",
       "        </body>\n",
       "        <script>\n",
       "            \n",
       "/*<!--*/\n",
       "call_DataFrame(function() { DataFrame.addTable({ cols: [{ name: \"<span title=\\\"untitled: Int\\\">untitled</span>\", children: [], rightAlign: true, values: [\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">1</span></span>\",\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">2</span></span>\",\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">3</span></span>\"] }, \n",
       "{ name: \"<span title=\\\"manufacturer: String\\\">manufacturer</span>\", children: [], rightAlign: false, values: [\"audi\",\"audi\",\"audi\"] }, \n",
       "{ name: \"<span title=\\\"model: String\\\">model</span>\", children: [], rightAlign: false, values: [\"a4\",\"a4\",\"a4\"] }, \n",
       "{ name: \"<span title=\\\"displ: Double\\\">displ</span>\", children: [], rightAlign: true, values: [\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">1.8</span></span>\",\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">1.8</span></span>\",\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">2.0</span></span>\"] }, \n",
       "{ name: \"<span title=\\\"year: Int\\\">year</span>\", children: [], rightAlign: true, values: [\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">1999</span></span>\",\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">1999</span></span>\",\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">2008</span></span>\"] }, \n",
       "{ name: \"<span title=\\\"cyl: Int\\\">cyl</span>\", children: [], rightAlign: true, values: [\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">4</span></span>\",\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">4</span></span>\",\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">4</span></span>\"] }, \n",
       "{ name: \"<span title=\\\"trans: String\\\">trans</span>\", children: [], rightAlign: false, values: [\"auto(l5)\",\"manual(m5)\",\"manual(m6)\"] }, \n",
       "{ name: \"<span title=\\\"drv: String\\\">drv</span>\", children: [], rightAlign: false, values: [\"f\",\"f\",\"f\"] }, \n",
       "{ name: \"<span title=\\\"cty: Int\\\">cty</span>\", children: [], rightAlign: true, values: [\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">18</span></span>\",\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">21</span></span>\",\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">20</span></span>\"] }, \n",
       "{ name: \"<span title=\\\"hwy: Int\\\">hwy</span>\", children: [], rightAlign: true, values: [\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">29</span></span>\",\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">29</span></span>\",\"<span class=\\\"formatted\\\" title=\\\"\\\"><span class=\\\"numbers\\\">31</span></span>\"] }, \n",
       "{ name: \"<span title=\\\"fl: String\\\">fl</span>\", children: [], rightAlign: false, values: [\"p\",\"p\",\"p\"] }, \n",
       "{ name: \"<span title=\\\"class: String\\\">class</span>\", children: [], rightAlign: false, values: [\"compact\",\"compact\",\"compact\"] }, \n",
       "], id: 654311424, rootId: 654311424, totalRows: 3 } ) });\n",
       "/*-->*/\n",
       "\n",
       "call_DataFrame(function() { DataFrame.renderTable(654311424) });\n",
       "\n",
       "\n",
       "document.getElementById(\"static_df_654311425\").style.display = \"none\";\n",
       "        </script>\n",
       "        </html>"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "val mpg = DataFrame.readCSV(\"https://raw.githubusercontent.com/JetBrains/lets-plot-docs/master/data/mpg.csv\")\n",
    "mpg.head(3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "e462696a",
   "metadata": {},
   "outputs": [],
   "source": [
    "val mpgData = mpg.toMap()"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "5360fc9a",
   "metadata": {},
   "source": [
    "#### 1. Data Type of the \"manufacturer\" is `Unordered Discrete` by Default "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "id": "6d24e699",
   "metadata": {},
   "outputs": [
    {
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       "},\n",
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       "\"data\":{\n",
       "\"..count..\":[18.0,19.0,37.0,25.0,9.0,14.0,8.0,4.0,3.0,4.0,13.0,5.0,14.0,34.0,27.0],\n",
       "\"manufacturer\":[\"audi\",\"chevrolet\",\"dodge\",\"ford\",\"honda\",\"hyundai\",\"jeep\",\"land rover\",\"lincoln\",\"mercury\",\"nissan\",\"pontiac\",\"subaru\",\"toyota\",\"volkswagen\"]\n",
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       "           var plotContainer = document.getElementById(\"49PPG7\");\n",
       "           window.letsPlotCall(function() {{\n",
       "               LetsPlot.buildPlotFromProcessedSpecs(plotSpec, -1, -1, plotContainer);\n",
       "           }});\n",
       "       })();    \n",
       "   </script>"
      ]
     },
     "execution_count": 5,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "letsPlot(mpgData) + geomBar() { x = \"manufacturer\" } + coordFlip()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "id": "0af44c65",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "dodge\n",
      "toyota\n",
      "volkswagen\n",
      "ford\n",
      "chevrolet\n",
      "audi\n",
      "hyundai\n",
      "subaru\n",
      "nissan\n",
      "honda\n",
      "jeep\n",
      "pontiac\n",
      "land rover\n",
      "mercury\n",
      "lincoln\n"
     ]
    }
   ],
   "source": [
    "// \n",
    "// Create a list of categories sorted according to a num. of vehicles in the dataset.\n",
    "// \n",
    "\n",
    "val brandsByCount = mpg.valueCounts { manufacturer }.manufacturer.toList()\n",
    "brandsByCount.forEach(::println)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "298c25fd",
   "metadata": {},
   "source": [
    "#### 2. Annotate \"manufacturer\" as a `Categorical` Using `asDiscrete(levels=..)` "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "id": "187a9fba",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
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       "\"column\":\"manufacturer\",\n",
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       "\"variables\":[\"..count..\"],\n",
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       "\"data\":{\n",
       "\"..count..\":[18.0,19.0,37.0,25.0,9.0,14.0,8.0,4.0,3.0,4.0,13.0,5.0,14.0,34.0,27.0],\n",
       "\"manufacturer\":[\"audi\",\"chevrolet\",\"dodge\",\"ford\",\"honda\",\"hyundai\",\"jeep\",\"land rover\",\"lincoln\",\"mercury\",\"nissan\",\"pontiac\",\"subaru\",\"toyota\",\"volkswagen\"]\n",
       "}\n",
       "}]\n",
       "};\n",
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       "       })();    \n",
       "   </script>"
      ]
     },
     "execution_count": 7,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "letsPlot(mpgData) + \n",
    "    geomBar(labels = layerLabels(\"..count..\").format(\"..count..\", \"d\"), tooltips = tooltipsNone) {\n",
    "        x = asDiscrete(\"manufacturer\", levels = brandsByCount) \n",
    "    } + \n",
    "    coordFlip()"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "bright-consequence",
   "metadata": {},
   "source": [
    "#### 3. Faceted Plots Respect the Order of Categories in Facet Variable\n",
    "\n",
    "However, it's fairly tricky to annotate a facet variable with `asDiscrete()`."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "id": "patent-edmonton",
   "metadata": {},
   "outputs": [
    {
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       "\"layers\":[{\n",
       "\"mapping\":{\n",
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       "\"fill\":\"drv\"\n",
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       "\"stat\":\"count2d\",\n",
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       "\"geom\":\"pie\",\n",
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       "\"..count..\":[7.0,11.0,5.0,4.0,10.0,11.0,26.0,13.0,12.0,9.0,14.0,8.0,4.0,3.0,4.0,9.0,4.0,5.0,14.0,19.0,15.0,27.0],\n",
       "\"..x..\":[0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0],\n",
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       "\"drv\":[\"f\",\"4\",\"f\",\"4\",\"r\",\"f\",\"4\",\"4\",\"r\",\"f\",\"f\",\"4\",\"4\",\"r\",\"4\",\"f\",\"4\",\"f\",\"4\",\"f\",\"4\",\"f\"],\n",
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       "\"facet\":{\n",
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       "};\n",
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       "   </script>"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "letsPlot(data = mpgData) {\n",
    "        // Utilize unused aesthetic just to annotate \"manufacturer\" as Categorical.\n",
    "        slope = asDiscrete(\"manufacturer\", levels = brandsByCount) \n",
    "     \n",
    "    } +\n",
    "    geomPie() { \n",
    "        fill = \"drv\"\n",
    "        size = \"..sum..\" \n",
    "    } +\n",
    "    facetWrap(facets = \"manufacturer\", ncol = 5, order = 0) + \n",
    "    scaleSize(range = 2 to 10) +\n",
    "    guides(size = \"none\") +\n",
    "    themeVoid()\n"
   ]
  }
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